1. Field of the Invention
The present invention relates to information processing devices and methods. In particular, the present invention relates to an information processing device and method that are capable of suppressing image-quality deterioration that occurs during transmission of image data.
2. Description of the Related Art
Various schemes have been proposed to encode image data. Examples include MPEG-2 (Moving Picture Experts Group 2) and AVC (Advanced Video Coding) technologies, which perform compression processing on multiple frames in a moving picture at a time by using inter-frame correlations and motion compensation, and Motion JPEG (Joint Photographic Experts Group) and JPEG 2000 technologies, which perform processing for each frame without using inter-frame correlations.
In general, the former technologies have characteristics of a high compression rate and a large amount of delay and the latter have characteristics of a small amount of delay and a relatively low compression rate. For main image-coding schemes of such technologies, a VBR (variable bitrate) is often used.
For example, Japanese Unexamined Patent Application Publication No. 2007-311924 discloses a scheme in which compression encoding based on wavelet transform is performed using multiple lines in each picture of a moving image as one compression encoding block. In the disclosed scheme, an encoding device can start compression encoding before all data in the picture are input. When compressed data is transmitted through a network and a receiving end decodes the compressed data, a decoding device can start decoding processing before receiving all data in the picture. Thus, when the amount of transmission delay in the network is sufficiently small, real-time moving-image transmission can be achieved with an amount of delay which is not greater than the frame intervals.
In general, image data are encoded and compressed using the above-described technologies and are transmitted as compressed data, in order to reduce the amount of load in a transmission channel. The bandwidth of the transmission channel is finite and thus the transmittable rate thereof has an upper limit. Thus, typically, a target bitrate of encoding is set smaller or equal to the upper-limit value of the transmission rate of the transmission channel.